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Can Scrapie be Transmitted to Humans?

ANALYSIS - New concerns have been raised over potential links between the sheep brain disease scrapie and human forms of the disease.

The potential connection has been shown in a new study published in the scientific journal Nature Communications.

The study, largely conducted at the Ecole Nationale Vétérinaire de Toulouse and with assistance from CISA- INIA in Madrid, the Norwegian Veterinary Institute, INRA in France and the UR892 Virologie et Immunologie Moléculaires research centre in France, shows that scrapie prions have a zoonotic potential.

The research team said that mice genetically engineered to overexpress the human prion protein (tgHu) have emerged as highly relevant models for gauging the capacity of prions to transmit to humans.

These models can propagate human prions without any apparent transmission barrier and have been used to confirm the zoonotic ability of BSE.

The researchers show that a panel of sheep scrapie prions transmit to several tgHu mice models with an efficiency that is comparable to that of cattle BSE.

The serial transmission of different scrapie isolates in these mice led to the propagation of prions that are phenotypically identical to those causing sporadic CJD (sCJD) in humans.

“These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions,” the French led team said.

Across the EU, there are measures in place to ensure that animals clinically affected with scrapie are not able to enter the food chain and regular surveillance is carried out in both abattoirs and on fallen stock.